The inception of genetic modification (GM) techniques in food production conveys both opportunities - improve food production technologies and/or product differentiation - and risks - dread of a change of the technological status quo, ambiguity in the food properties..…. Hence, some research has been devoted a careful understanding of consumer's reactions towards to GM food. However, unavoidably individual's perceptions involve taking into account several factors at a time that cannot be taken as given or exogenous such as traditional food values and trust in information sources primarily. This paper contributes to the literature by examining the behavioural process that drives individual's perceptions to GM food using a methodology that allows accounting for such effects. Structural Equation Model or causal modelling allows to examine a system of interdependent effects driving consumers' decision-making process. We undertake an empirical application in three specific Mediterranean countries, namely Spain, Italy and Greece where traditional values, such as Mediterranean diet, contrast that of modern benefits of technology. We argue that public attitudes towards GM food are formed as a result of a reasoning mechanism that departs form trust in science and in public authorities and ultimately affects consumer's final purchase decision. Our finding suggests marked differences in the reasoning mechanism that leads to the acceptance of GM food in the three different countries examined.